Hay-Fever vs. Histamine Intolerance: What’s the Difference?

If you suffer from itchy eyes, a runny nose, sneezing and nasal congestion, you might attribute your symptoms to hay-fever. After all, hay-fever is indeed associated with all of these symptoms…but so too can be histamine intolerance. These two conditions can be very similar in their presentation, but the underlying cause (and therefore the way we treat it) can be very different.

So what is histamine intolerance, and how is it different to hay-fever?

Histamine intolerance occurs when the body has difficulty managing and metabolising histamine, allowing it to build up in the system. Histamine is a chemical that is both made by the body and found in the foods we eat. An excess of histamine can cause a wide range of symptoms, including:

As you can see, symptoms of histamine intolerance can be very similar to some of those associated with hay-fever, including sinus problems, nasal congestion and fatigue. The difference lies in the cause:

Hay-fever (or ‘allergic rhinitis’) occurs due to an allergic response to common airborne substances, such as pollen, grass, dander and dust. It is a true allergy, which means it can been seen on blood tests measuring certain allergy markers.

Histamine intolerance occurs due to a build-up or excess of histamine in the body. To breakdown histamine, we need an enzyme called diamine oxidase (DAO). Some people produce insufficient DAO relative to the amount of histamine they make or consume, resulting in histamine intolerance.

How does histamine intolerance occur?

Some of the factors that can contribute to the development of histamine intolerance include:

Use of medications that inhibit histamine breakdown (like antibiotics, certain pain medications and some anti-depressants).

Having the wrong types of bacteria in the digestive tract, resulting in increased histamine production.

Other factors that can make you more susceptible to histamine intolerance include certain nutritional deficiencies (e.g. vitamin B6 or zinc), some gastrointestinal conditions, prolonged stress and liver dysfunction.

What can you do about it?

The first step is to identify whether your symptoms are the result of a true allergy (e.g. hay-fever) or an underlying histamine intolerance. In some cases, taking a closer look at your symptoms might help point you in the right direction. For example, if your symptoms occur seasonally, such as with the onset of Spring, chances are you’re experiencing hay-fever. If you notice your symptoms occur year round but are particularly bad after a wine and cheese night, it’s possible you may have histamine intolerance. Our naturopaths can also request blood tests that can distinguish between hay-fever or histamine intolerance, so we can address the symptoms at the cause. It’s important to remember the two conditions can also occur simultaneously, so working with a naturopath can help you address both conditions at once.

If histamine intolerance is an issue for you, some of the other things you can do include: